# All We Know About Maximizing CPU Related Performance

#### Tutor

##### macrumors 65816
Hi Tutor, well I tried upped it from 1066 to 1333 & CR 1, then input 9-9-9-25; wouldn't start up. Then tried 9-10-9-26 and only 40GB would work, then tried 9-11-9-27 and only 32GB would work.

I know that you mentioned that keeping it at 1066 would bring to 1333, but I'm gathering taking to 1333 would take it to a higher Mhz. I will wait for your input...
Try 9-11-9-27 and set first CPU's ram to 1.65 V and the second to 1.66 V. and if that doesn't work keep voltage 1.65/1.66 and try 9-11-10-28. Here's some more math: 165/133 (BCLK) = ~1.24; ~1.24 x 1333 = 1653.72 MHz.

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#### SR2Mac

##### macrumors regular
Try 9-11-9-27 and set first CPU's ram to 1.65 V and the second to 1.66 V. and if that doesn't work keep voltage 1.65/1.66 and try 9-11-10-28. Here's some more math: 165/133 (BCLK) = ~1.24; ~1.24 x 1333 = 1653.72 MHz.
I followed you input and everything was already set to 1.65/1.66 (from the beginning as you instructed for me to do before), so I let be and I then tried the next one up from 9-11-9-27 (since that didn't work from the last try). As that only allowed me to utilize 32GB of RAM. Well I tried 9-11-10-28 and this time it allowed me to utilize 40GB of RAM. So what are your thoughts now? Thanks...

#### Tutor

##### macrumors 65816
I followed you input and everything was already set to 1.65/1.66 (from the beginning as you instructed for me to do before), so I let be and I then tried the next one up from 9-11-9-27 (since that didn't work from the last try). As that only allowed me to utilize 32GB of RAM. Well I tried 9-11-10-28 and this time it allowed me to utilize 40GB of RAM. So what are your thoughts now? Thanks...
Change that last 9 to 10 and that 28 to 29.

#### SR2Mac

##### macrumors regular
Change that last 9 to 10 and that 28 to 29.
I didn't need to change the last 9 as it was already set at 9-11-10-28. So all I did was change the 28 to 29 and it started then shut right down... Okay, any more thoughts...

#### Tutor

##### macrumors 65816
I didn't need to change the last 9 as it was already set at 9-11-10-28. So all I did was change the 28 to 29 and it started then shut right down... Okay, any more thoughts...
Forgot to mention that, at least, in my bios that EVGA has ordered the parameters differently than most others. They put tRAS 2nd rather than fourth.
With that caution in mind, I'm running my memory at a tight 6-20-7-7. Try it.

#### SR2Mac

##### macrumors regular
Forgot to mention that, at least, in my bios that EVGA has ordered the parameters differently than most others. They put tRAS 2nd rather than fourth.
With that caution in mind, I'm running my memory at a tight 6-20-7-7. Try it.
Well, This is how it's set up for my SR-2 Mobo so it should then be:

DRAM tCL - 6
DRAM tRCD - 7
DRAM tRP - 7
DRAM tRAS - 20

I will try it and see what happens...

#### SR2Mac

##### macrumors regular
Forgot to mention that, at least, in my bios that EVGA has ordered the parameters differently than most others. They put tRAS 2nd rather than fourth.
With that caution in mind, I'm running my memory at a tight 6-20-7-7. Try it.
I input the new info and now it's saying (on the 2 digit LED on the mobo):

00 - E8 - 02 - 69

and it keeps repeating and that's it. No screen, nothing. Now what can we do...

#### Tutor

##### macrumors 65816
Well, This is how it's set up for my SR-2 Mobo so it should then be:

DRAM tCL - 6
DRAM tRCD - 7
DRAM tRP - 7
DRAM tRAS - 20

I will try it and see what happens...
Then try
DRAM tCL -6
DRAM tRCD - 8
DRAM tRP - 7
DRAM tRAS - 21

General rules (but they can be broken when you know parameters completely):
1) tCL + tRCD + tRP = tRAS
2) tRCD is the most sensitive, so increase it first to achieve stability; then tRP next.
3) tCL is the least sensitive, so increase it last.
4) I'm almost certain that you will not have to change the command rate from 1.
5) Using these general rules means that I'll go up two steps [(but only on one parameter at a time) for tRCD and then tRP] before increasing tCL one step. Then repeat the process.

Here's additional adjustments to eck out that last bit of extra performance, but make sure that you've saved your last, best settings first. Also keep in mind that a flaw in all of the bioses only allows you to save one profile, even though there appears to be 4 spaces to save them/it.

QPI - 5.8+ rather than 4.8+

Frequency/Voltages
CPU0 Vcore Boot - 1.33125
CPU1 Vcore Boot - 1.31875
CPU0 Vcore Eventual - 1.34375
CPU1 Vcore Eventual - 1.33125
Boot CPU VTT - 1.375 (both CPUs)
Eventual CPU VTT - 1.4 (both CPUs)
DimmCPU0 Vcore 1.65
DimmCPU1 Vcore 1.66
IOH - 1.4
CPU PLL (both CPUs) - 1.845
CPU PWM Freq - 1210 (both CPUs)

Signal tweaks
PCIe - Auto (both CPUs)
Max positive values for: IOH, CPU to CPU (both directions), all CPU DDR
Max negative values for: both CPU Impedance and both QPIs

Caveat: Mileage may vary, but these get me over a 35,000 score for Geekbench2 using the same base CPU frequency as your system. http://browse.geekbench.ca/geekbench2/581886

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#### SR2Mac

##### macrumors regular
Then try
DRAM tCL -6
DRAM tRCD - 8
DRAM tRP - 7
DRAM tRAS - 21

General rules (but they can be broken when you know parameters completely):
1) tCL + tRCD + tRP = tRAS
2) tRCD is the most sensitive, so increase it first to achieve stability; then tRP next.
3) tCL is the least sensitive, so increase it last.
4) I'm almost certain that you will not have to change the command rate from 1.
5) Using these general rules means that I'll go up two steps [(but only on one parameter at a time) for tRCD and then tRP] before increasing tCL one step. Then repeat the process.

Here's additional adjustments to eck out that last bit of extra performance, but make sure that you've saved your last, best settings first. Also keep in mind that a flaw in all of the bioses only allows you to save one profile, even though there appears to be 4 spaces to save them/it.

QPI - 5.8+ rather than 4.8+

Frequency/Voltages
CPU0 Vcore Boot - 1.33125
CPU1 Vcore Boot - 1.31875
CPU0 Vcore Eventual - 1.34375
CPU1 Vcore Eventual - 1.33125
Boot CPU VTT - 1.375 (both CPUs)
Eventual CPU VTT - 1.4 (both CPUs)
DimmCPU0 Vcore 1.65
DimmCPU1 Vcore 1.66
IOH - 1.4
CPU PLL (both CPUs) - 1.845
CPU PWM Freq - 1210 (both CPUs)

Signal tweaks
PCIe - Auto (both CPUs)
Max positive values for: IOH, CPU to CPU (both directions), all CPU DDR
Max negative values for: both CPU Impedance and both QPIs

Caveat: Mileage may vary, but these get me over a 35,000 score for Geekbench2 using the same base CPU frequency as your system. http://browse.geekbench.ca/geekbench2/581886
I input what you instructed and it FF'd on me, so nothing... You really show dedication, I'll say that. But I'm here willing to try anything...

#### Tutor

##### macrumors 65816
I input what you instructed and it FF'd on me, so nothing... You really show dedication, I'll say that. But I'm here willing to try anything...
Then go back to your last, best performing, stable settings, with memory set to 1333 MHz / auto. Reboot. Open bios and note what actual numbers auto has allocated to your ram for tCL, tRCD, tRP, tRAS and command rate. Now set each of those values explicitly to your ran, reboot and try, using the general rules set forth in my last post, to tighten the memory better than auto does, but with no preconceived goal in mind. Just decrease one value one step at a time, starting with the less sensitive ones first, reboot / geekbench. When instability occurs, reverse the last decrease preceding it. This you have to do on your own because every system even if built with exactly the same parts and software will have different performance limits. Time for you to abandon the nest and learn all that you can; then apply that learning to extend beyond what I've taught you to make even greater discoveries and pay it forward by helping others. I am, however, for as long as God blesses me with life, only a post or PM away.

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#### SR2Mac

##### macrumors regular
Then go back to your last, best performing, stable settings, with memory set to 1333 MHz / auto. Reboot. Open bios and note what actual numbers auto has allocated to your ram for tCL, tRCD, tRP, tRAS and command rate. Now set each of those values explicitly to your ran, reboot and try, using the general rules set forth in my last post, to tighten the memory better than auto does, but with no preconceived goal in mind. Just decrease one value one step at a time, starting with the less sensitive ones first, reboot / geekbench. When instability occurs, reverse the last decrease preceding it. This you have to do on your own because every system even if built with exactly the same parts and software will have different performance limits. Time for you to abandon the nest and learn all that you can; then apply that learning to extend beyond what I've taught you to make even greater discoveries and pay it forward by helping others. I am, however, for as long as God blesses me with life, only a post or PM away.
I do realize that and had a feeling that it wasn't going to work out too well. I will now go back to the next best reliable BIOS settings (from post #69). Then try what I can with the RAM. At least it can handle many hours of TT under the AUTO RAM settings; just so long as I don't use any other apps in the process (as I'm using 24 Terminal.app pages using the yes > /dev/null command on each page to put 100% stress on every virtual core). So at least we have success in that area.

When the RAM is set to default, it will go back to [AUTO] 7-7-7-20 / Command Rate 2. From what you said,

Now set each of those values explicitly to your ram,
did you mean that I have to type in 7-7-7-20 / Command Rate 2 and NOT keep it on [AUTO]?

Lastly, is it a bad thing to keep the Command Rate set on 2 or should it always be set to 1? I'll work on figuring the rest out on my own. Thanks again for all your input !!! Oh, and by the way, if anyone tries to disprove your method of it not working, then you can always bring them here and show them my GB scores as well as yours. I'll be the additional proof that UNDERCLOCKING DOES WORK & IS FAR BETTER FOR MORE EFFICIENT & FASTER RENDERING !!!

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#### Tutor

##### macrumors 65816
SR2Mac said:
... . From what you said, did you mean that I have to type in 7-7-7-20 / Command Rate 2 and NOT keep it on [AUTO]? ...
Please type in 7-7-7-20. Auto for Command Rate is potentially faster than Command Rate 2 which allows only the slower rate - so leave this one set to Auto for now.

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#### SR2Mac

##### macrumors regular
Please type in 7-7-7-20. Auto for Command Rate is potentially faster than Command Rate 2 which allows only the slower rate - so leave this one set to Auto for now.
Thank you once again. I will try it and let you know my results on the GB scoring page (#2)...

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#### SR2Mac

##### macrumors regular
Hi Tutor,
I'm going to input those settings here soon, but I wanted to find out first how do I get the CPU temps to read on apps like iStat and smck-stat-i? I know that I asked this before, but I also know that barraged you with many other questions as well... LOL !!!

I tried to find something online on this topic but not haven't found anything on it...

#### Tutor

##### macrumors 65816
Hi Tutor,
I'm going to input those settings here soon, but I wanted to find out first how do I get the CPU temps to read on apps like iStat and smck-stat-i? I know that I asked this before, but I also know that barraged you with many other questions as well... LOL !!!

I tried to find something online on this topic but not haven't found anything on it...
I run http://www.projectosx.com/forum/index.php?showtopic=1206&hl=K-stat-i k-stat-i.

#### SR2Mac

##### macrumors regular
Yup, that the very one that I just mentioned that I tried using, but it doesn't seem to want to work, nor does any of the 5 or 6 CPU temp apps out there. I think there's some kext file or something that is blocking it from being available for me to use. When I was using 3,1 the CPU temps (all cores) were reading just fine on iStat, but now using 5,1 it doesn't work anymore. Well I guess all I have to do is just look at mobo to see the temps. But I think that's for the mobo and not the CPUs. Any other suggestions as I've been trying to find one would be great... thanks...

#### Tutor

##### macrumors 65816
Yup, that the very one that I just mentioned that I tried using, but it doesn't seem to want to work, nor does any of the 5 or 6 CPU temp apps out there. I think there's some kext file or something that is blocking it from being available for me to use. When I was using 3,1 the CPU temps (all cores) were reading just fine on iStat, but now using 5,1 it doesn't work anymore. Well I guess all I have to do is just look at mobo to see the temps. But I think that's for the mobo and not the CPUs. Any other suggestions as I've been trying to find one would be great... thanks...
Difference has to be a kext file, bootloader file, cpu or bios difference because otherwise our systems are the same.

##### macrumors member
Up and running....

Waiting for a working Ethernet PCI card, but my new SR-2 "Mac Pro" is up and running, Turbo 111122 for stock....

#### SR2Mac

##### macrumors regular
Waiting for a working Ethernet PCI card, but my new SR-2 "Mac Pro" is up and running, Turbo 111122 for stock....

http://www.directron.com/sdpex24009.html

I tried to use lnx2mac's custom ethernet kext file (here: http://lnx2mac.blogspot.com/p/realtekrtl81xx-osx-driver.html), but to no avail. He even tried as best as he could to help me, but still nothing. Then, I just trashed his file and guess what? It worked, would you believe it?

BTW, I bought two (since they're just \$12.99 a piece), just in case one craps out on me I'll have another. Hope this helps you. Later...

#### SR2Mac

##### macrumors regular
Hi Tutor,

I'm a bit discouraged today as I'm trying to find out why my mobo is FF'ing on me? I took out my EVGA GTX 480 and put in it's place a EVGA GTX 580 (which is actually pulling less wattage) and that's when it FF'd on me. Then I took it out and put back the 480 and it booted fine. Obviously I'm thinking it's the card, right? Well, I put the 580 in my Gigabyte UD7 setup and the 580 works just fine. Then I decided to disconnect everything and let the system just sit for 2+ hours instead of the 5 to 30 min. minimum, (I found that out on another post somewhere). Then I reconnected everything back together, put the battery back on the mobo, and reset the CMOS and the system started right up. But I needed this particular file (found here: http://www.osx86.net/view/2074-gtx_5xx_enabler.html) to make the 580 card fully work at ALL resolutions and not just 1024 x 768. So while I was downloading the file I CCC'd the SSD as it was last saved; just in case this new enabler messed something up.

Well, after I was done CCC'ing everything and getting that enabler file the machine just froze after I was done with everything. That never happened before. I tried restarting and it FF'd again... At this point I decided to try just using the XFX Radeon HD 6870 GPU and it still just FF'd. So I don't know what the issue is. I'm wondering if it's the PSU (Silverstone ST-1500) or just the mobo itself? No real way to know. Any thoughts or input would be greatly appreciated... Thank you...

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#### Tutor

##### macrumors 65816
Waiting for a working Ethernet PCI card, but my new SR-2 "Mac Pro" is up and running, Turbo 111122 for stock....
Here's a summary of what Sr2Mac and I did:

1) Run Geekbench2 64-bit and note your score.
2) Make sure that ACPI/HPET are enabled - Power Management menu on main bios screen/ACPI Config/General *choose s3 and Under Chipset Config choose High Precision Event Timer (HPET);
3) Install, in your Extra folder, the correct DSDT.aml file from d00d's post #1 at his nativepowermanagement thread at insanelymac.
4) Make the appropriate changes to info.plist in FakeSMC.kext as set forth in post #'s 53-57, above;
5) Delete NullCPUPower Management.kext if you have it installed;
6) Make sure that org.chameleon.Boot.plist (Lion) or smbios.plist(SL) (in your Extra folder) does not have any references to either 3,1 or 4,1 by changing them to 5,1 . Also, make sure that the following settings are in the contents of org.chameleon.Boot.plist after having stored an unmodified copy of org.chameleon.Boot.plist to that file that you create and name "UseOnlyIfNeeded" folder; then save the change:
<key>DSDT</key>
<string>/Extra/DSDT.aml</string>
<key>ForceHPET</key>
<string>No</string>
<key>GenerateCStates</key>
<string>No</string>
<key>GeneratePStates</key>
<string>No</string>
7) Rebuild boot cache.
8) Reboot and follow posts#'s #18 (except set CPU frequency to 162 for starters), 29, 61 and 71 for tweaking bios.
9) Run Geekbench2 64-bit and compare the old and new scores. Then reread thread again and hopefully it will help you with any problems and when you come to tweaking the ram.

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#### SR2Mac

##### macrumors regular
I'm stepping aside to let SR2Mac pay it forward and spread his wings. It'll help him grow as he helps you. Thus, he'll be the primary assist and I'll step in only as needed.
Funny that you posted this comment as I'm still seeking input as to why my my system is FF'ing on me and not posting. I will continue to work on a solution as the tech guys at EVGA (like Gabriel) and Joel at SilverstoneTek (with the PSU) are trying to give me some solutions to help me figure out my issue.

#### Tutor

##### macrumors 65816
Hi Tutor,

I'm a bit discouraged today as I'm trying to find out why my mobo is FF'ing on me? I took out my EVGA GTX 480 and put in it's place a EVGA GTX 580 (which is actually pulling less wattage) and that's when it FF'd on me. Then I took it out and put back the 480 and it booted fine. Obviously I'm thinking it's the card, right? Well, I put the 580 in my Gigabyte UD7 setup and the 580 works just fine. Then I decided to disconnect everything and let the system just sit for 2+ hours instead of the 5 to 30 min. minimum, (I found that out on another post somewhere). Then I reconnected everything back together, put the battery back on the mobo, and reset the CMOS and the system started right up. But I needed this particular file (found here: http://www.osx86.net/view/2074-gtx_5xx_enabler.html) to make the 580 card fully work at ALL resolutions and not just 1024 x 768. So while I was downloading the file I CCC'd the SSD as it was last saved; just in case this new enabler messed something up.

Well, after I was done CCC'ing everything and getting that enabler file the machine just froze after I was done with everything. That never happened before. I tried restarting and it FF'd again... At this point I decided to try just using the XFX Radeon HD 6870 GPU and it still just FF'd. So I don't know what the issue is. I'm wondering if it's the PSU (Silverstone ST-1500) or just the mobo itself? No real way to know. Any thoughts or input would be greatly appreciated... Thank you...
I'm strictly an ATI man. However, try booting at default speed/Vcore settings and all memory parameters set to auto. "FF" is usually indicative of too high a BCLK, QPI or memory speed. Always use factory settings for new installations of hardware and software.

#### SR2Mac

##### macrumors regular
I'm strictly an ATI man. However, try booting at default speed/Vcore settings and all memory parameters set to auto. "FF" is usually indicative of too high a BCLK, QPI or memory speed. Always use factory settings for new installations of hardware and software.
Well, as mentioned before I did use my ATI (6870) GPU and it still FF'd. It does that immediately when I boot the machine; even when I reset the CMOS on it, I won't do anything else, just FF. So I don't know what's going on?... But I'm going to have to figure this out, thank you Tutor anyway for your suggestions...

#### Tutor

##### macrumors 65816
Funny that you posted this comment as I'm still seeking input as to why my my system is FF'ing on me and not posting. I will continue to work on a solution as the tech guys at EVGA (like Gabriel) and Joel at SilverstoneTek (with the PSU) are trying to give me some solutions to help me figure out my issue.
Even as you encounter new problems, it does not diminsh what you've learned. Clearly, I don't know everything. But does that mean that I cannot help others by imparting what I do know. View each new obstacle as an opportunity to increase your knowledge base so that you can help others with those kinds of problems. And never forget that the more you learn, the better will be your guesses.